Tara and Dawn wake on the couch and find that neither Buffy nor Willow returned home the night before. Buffy wakes up naked with Spike to find the building around them fell down as she remembers what they did. Spike tempts Buffy as she tries to leave (such as showing her her own thong) and reminds her of everything they did the night before. He angers and disgusts her and she leaves, threatening to kill him if he tells anyone about their tryst.
Amy returns home with Willow and rambles about Willow's amazing magical use in front of Tara and Dawn. Tara leaves as Buffy returns as well and after a chat, Amy leaves and Buffy and Willow go to bed after their long nights. Willow tries to shut the drapes of her room with magic, but she is out of mana. Anya reads bridal magazines instead of researching the freezing demon. At the magic shop, Xander, Anya and Buffy discuss Willow and her behavior and Buffy comes to Willow's defense.
Amy suggests Willow and she visit a warlock, Rack, who can give them great spells that last without any recovery time. The house is cloaked and filled with the magically addicted, seeking a fix. Rack takes a "tour" of Willow's body before giving her what she came for. Amy spins about the room wildly as Willow hangs out on the ceiling, seeing spots and weird images. The next morning, Willow wakes in her own room and cries in the shower. She manipulates some of Tara's clothes to form an invisible body and curls up against it.
Dawn makes some interesting food and makes plans to see a movie with Willow. Buffy returns home to find Amy stealing some of Willow's magical supplies. Buffy scolds her as Amy behaves obsessively about the supplies and tells Buffy about Willow's whereabouts. Willow and Dawn talk about food and Tara then take a detour to Rack's place so Willow can get a fix. Dawn waits impatiently in the waiting room with a freaky man. Meanwhile, Willow floats in Rack's room and sees herself flying in space before a demon holding a limp body makes her scream.
Buffy wakes a very naked Spike and demands his help in finding Willow and Dawn. Dawn is mad Willow left her so long and Willow's carefree attitude makes Dawn nervous and eager to return home. Buffy refuses to admit she likes Spike and he again reminds her how much she really wants and needs him. A demon confronts Willow, claiming that she summoned him with her use of magic. The demon cuts Dawn and the girls run. Willow uses magic to take over and drive a car, but it crashes and both are wounded.
Dawn finds that she has a broken arm as Willow is knocked out against the steering wheel. The demon catches up with their wrecked car and Dawn tries desperately to fight it off. Spike and Buffy, who heard Dawn scream come to the rescue. Buffy fights the demon while Spike takes care of Buffy's wounded younger sister. Suddenly the demon explodes into flames as a result of a killing spell cast by Willow.
Despite Willow's sincere apology and tearful regret, Buffy tells her to stay back and Dawn slaps her away in anger. Spike takes Dawn to the hospital and Buffy gets furious with a sobbing Willow who's frightened and begs for help. At the house, Buffy talks with Willow about her abuse of magic and the consequences. Willow says she's giving up magic for good and Buffy agrees with that. She also senses the connection between Willow's magic use and her own situation with Spike. Later, Willow fights the symptoms of withdrawal in her bed while Buffy hugs a cross and surrounds her bedroom with garlic.